Pneumatic tool.



H. SCHUMACHER.

PNEUMATIC TOOL.

APPLIOATION FILED 0013.28, 1909.

984, 1 1 2. N Patented Feb. 14, 1911.

3 SHEBTS-SHEET 1 H. SGHUMAGHER.

` PNBUMATIU'TOOL.

APPLICATION HLED 00128, 1909,

` 984,112. Patented Feb.14,1911.

3 SHEETS-SHEET 2.,

` H. SGHUMAGHBR.

PNEUMATIG TOOL. LPPLIOATION FILED 00T. $8, 1909.

Patented 11611111911.

PNEUMATIG TOOL.

HENRY SCHUMACHEB, 0F DENVER, COLORADO.

Speoication of LettersA Patent.

Patented Feb. 14, 1911.

i Application filed October 2B, 1909. Serial No. 525,189.

To all 'whom it may concern.'

Be it known that I, HENRY SOH'UMACHER,

Colorado, have invented certain new and useful Improvements, in yPneumatic Tools; and I dovdeclare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the4 letters and figures of referencevmarked thereon, which form a part of this specification.

My invention relates generally to' pneumatic tools, but more specially to motiveiluid-operated' engines or motors having a cylinder and a reciprocating piston connectedwith a device to be operated byfimparting a reciprocating movement. present instance the engine is illustrated in connection with a saw. It is evident, how

ever, Vthat any other device may be connected with the stem of the piston and it will therefore be understood that the use of the engine or motor is not limited to the operation of the particular device shown. It may. be stated, however, that myimproved construction of engine or motor is exceedingly well adapted for use in `operating asaw, and the latter is therefore illustrated in the drawin Tn my improved engine, I employ a longitudinally-movable bushing, or sleeve,

mounted in the -chamber of the cylinder and havin 'a limited degree of movement for. contro ling the admission and exhaust of .motive fluid for operating the piston, the latter being located within the bushing,- which -is closed at both ends.

Provision is made for admitting motive iluid from the piston chamber of the bushing, to the opposite ends of thecylinder, be-

tween the closed ends 'ofthe bushing and the extremities of the cylinder chamber, for automatically shiftin the bushing longitudinally, to control t e ladmission and ex-v haust of motive liu-id for operating the piston as above stated. Y

Iflaving brieiy outlined my improved construction, I will proceed to `describe the same in detail, reference being made t0 the accompanying'drawing,in which is illustrated an embodiment thereof. f

In this drawing:` Figure 1 is a longitudinal sectiontaken through the engine or moarrow adjacent said. line.

In the` tor, the saw frame being also shown partly in section. Fig. 2 is a section shown on the line 2 2, Fig. 1. Fig. 3 is a horizontal section takenonI the line .3 3,.Fig. 1, looking downwardly, or in the direction of the Fig. 4 'is a detail `view of the bushing movabl mounted within the cylinder and actuated y the piston to openV and close the induction ports at the opposite extremities of the cylinder. Fig. 5 is a longitudinal sect-ion of the cylinder 'shown in detail. Figs.' 6, 7 and V8 are cross sections taken onl the lines 6 6, 7 7, and 8 8, respectively, Fig...1. Fig. 9 is a side view of a sli htly modified form of the device, shown, orthe most part, in elevation, the saw portion of the device being partly broken away. Fig. 104 is a cross-section taken on the line 10 l0'of.Fig. 9.'

- The same reference characters indicate the same parts in allthe views.

Let the numeral 5 designate a` cylinder,

`by the guide'is securely held in place. This from the forward Y guide projects forwardl extremity .of theA cylinder and is provided with a longitudinal lgroove 14, adapted to receive the back 15 of ay saw frame, which has a forwardly-located, downwardly-l extendin v part 16, and;` a 'rearwardly-located, depen ing lpart17. 4 The. saw blade 18 isattached to t e lower extremitiesof the parts 16 and 17.

Located :vit-hin the c linder 5 is a longi tudinally-movable bushing 18A having rearwardly-located lports ,19,- and 20, and for wardly-located ports 21l and 22.. They cylinder, withinl which the bushing is movably mounted, is provided with interior, circunb' ,ferentialarran ed 1n the order named from the rearv omessa, 24,25, 26, `27 and 2s ltowar thefront'extremity of the cylinder. Within the bushing. 18A, a piston 29 is mounted to. reciprocate. This piston is providedV with -a stemy 30. which Vprotrudes through an openin' 31 formed inthe forward end ,32 of the ushing.18. `This piston stem passes throughv a stuling box 33, located in the forward headv 7 Vof the cylinder, the said sof head being open to receive the piston stem. The. forward extremity 34 of this stem protrudes beyond the cylinder and is connected with the rear member 17 of the saw frame. the piston stem being threaded into a threaded opening in the said frame and secured by a` lock nut l-Vhen the device is in use, the piston is reciprocated in the cylinder bushing through thel instrumentality of motive fluid admitted thereto and suitably Controlled to perform the vaforesaid function. The mechanism whereby this function is performed will now be described in detail.

Connected with the lower part of the handle 6, is a conduit 3G, which is in communication by means of a port 37', with a chamber 38, in which is located a valve 39 normally held at its rearward limit of movement 4by a spiral spring 40. This normal position of the valve cuts off the air, or other motive fluid, from the cylinder of the device. The valve is provided with a rearwardly-extending stem 41-,.arranged to be acted on by the arm 43 of a lever 42, fulcrumed at 44, in a recess 45, formed in the handle of the tool. lThis lever is arranged to be actuated by a lever 46, fulcrumed at 47, and having a protruding extremity 48, conveniently constructed and arrangedv to be operated by the hand of the user, while grasping the handle of the tool. The lower arm 49 of the lever 46 occupies a position in front of the 'upper extremity of the lever 42.

The handle of the tool is provided with-a passage 50 communicating with a duct 51, which is in communication with a port 52 formed in the wall of t-he cylinder and communicating with the interior circumferential groove 23 of the-cylinder.

Assuming that the parts vare in the position shown in Fig. 1 and also assuming that the valve 39 is shifted to uncover the ports 37, the motive Huidv will fiow through the passage 50, thence to a circumferential groove 53 at the rear of the cylinder, 'thence through ports 54 in the rea'r head 55 of the cylinder, thence to a duct'l `and a passage 56 leading to the ports l52 formed in the cylinder and communicating with the interior, circumferential groove 23 of the cylinder, and thence through bushing 18A, to the rear vo the piston `29. This live mot-ive fluid imparts the forward movement to the-piston land also the forward stroke to the saw or other device, by virtue of `the fact that the latter is connected with the iston stem. lAt the same time the. motive uid flows throu h the passage 56 to the forward extremity of the cylinder, where the said passage communicates' with the circumferential groove 28 of the cylinder. As the piston, duringits -forward movement,'approaches the forward e'xtremity of the bushing, it uncovers a port orts 19 of the A of the bushing communicating with the groove 26 of the cylinder, the latter being in tommunication with a passage B in the Wall of the cylinder and extending rearwardly to the rear extremity of the cylinder with which it communicates by a port C. The live motive fluid enters the port A of the bushing, passing thence to the groove 26 of thc cylinder and thence through the passage, B to the rear of the cylinder, entering the chamber of the cylinder through the port C, acts on the read head D of the bushing, moving the latter forwardly. In this event, the parts are in the position shown in Fig. 3, and the live motive fluid exhausts from the piston chamber through the port 20 of the bushing, the groove 24 of the cylinder and the port GO of the cylinder. At the same time the live motive Huid flows through the passage 56 to the forward extremity of the piston chamber, which it ent-ers through the groove 28 of the cylinder and ports 22 formed in the bushing, which are now in register with the groove 28 of the cylinder. The entrance of this live motive fluid to the forward extremity of the piston chamber results in the rearward movement of the piston, which imparts a corresponding movement to the saw. As the piston approaches its rearwardlimit of movement, it uncovers a. port E in the bushing, the latter being in communication with the annular groove 25 of the cylinder, the latter communicating with a passage F leading rearwardly from the groove 25, the said passage being formed in the wall of the cylinder and entering the rear extremity of the cylinder chamber through va port G. The live motive fluid following the ports and passages last stated enters the cylinder chamber forward of the front head of the bushing and imparts the rearward movement to the latter, whereby the parts are returned to the position illustrated in Fig. 2, after which the operation heretofore'described is repeated, thus imparting the reciprocating movement to the saw. After the piston has completed its rearward movement, as last explained, the

motive fluid in the piston chamber forward of the piston exhausts through the bushin ports 21, the annular cylinder groove 2g and an exhaust port 62, formed in the cylinder. (See Figs. 3 and 7.)

The'bushing 18A is provided with small ducts 61 located near its opposite extremities, these ducts in the forward extremity of the bushing having their rear extremities in communication with the annular groove 27 0f the cylinder, whereby the motive fluid forward of the front head 'of the bushing is allowed to leak out of the portion ofthe piston chamber forward of the said bushing head, in order to permit the bushing to move forwardlyl just before thel piston completes its forward movement.

It will be understood from an inspection of the drawin ,-that the'rear extremltes of the forward uctsl of the bushing, arey in a cross sectional plane cutting the ports 21 of the bushing. Hence f the live motive fiuidin leaking outl through the ducts 61,"

passes 'first into the annular grooves 27 oi the cylinder and thence through the ports 21 ofthe bushinginto the piston chamber ofy the bushingywhilewhen the bushing is at p its forward limit of movement and While the piston is making its forward stroke, the mo`r tive `Huid in the rear of the rear head D of the bushing, leaks outthrough the forward ducts`61. of the bushing into theannular groove 24- of the cylinder and thence through the bushin ports 20 into the piston chamber of` the bus ing.

The forward extremity ofthe cylinder is provided with' a depending auxiliary handle v 63 havin `a` stud 64 4inserted in a threaded tially interposedy and longitudinally-movable n between the piston and the cylinder, and means forktlie automaticadmission of moy tive fluid from the piston cylinder 'of the bushing alternately to `the oppositeextremil ties of the cylin r chamber, for'shifting. i

the bushing to control the admission and exi: haust of motive fluid in operatin the pistoh, the opposite ends 4of the bushin aving rela- `tivelysmall vpassages to admit the motive fluid between the opposite ends of the bushingand the adjacent extremities of the cyl- 1n er chamber, to leak intothe bushing to -permit the latter to move longitudinally in the cylinder.

\ 2.- In an engine or motor, the combination with: a cylinder and a reciprocating iston,

of a cylindric sleeve or bushmgloeatetfwithin the chamber of -the` cylinder, the piston being located within the said sleeve, the sleeve v `andcylinder having induction and eduction ports, and alsoprovidcd'with ports and passages for the automatic admission of motive fluid from the piston chamber of the bushing to' theopposite extremities of thecylinder, for alternately shifting'the bushing in' oppositedirections to control the admission and* exhaust of motivepltluid, the cylinder having' circumferential grooves withwhic'h the ports of they cylinder communicate,v the opposite ends of thesbushing having relatively small passa es communicating respec- Y tivelyy with one o the grooves in the opposite ends of the cylinder chamber to admit the motive fluidl between the ends of the bushing and the opposite extremities of the cylindergjt-o leak out in time to permit the longitudinal movement of the bushing, as

' described.

`In testimony whereof I aiiix my signature in presence of'two Witnesses. Y

HENRY SCHUMAGHER. t Witnesses: i l

A; J. OVBRmN, JEssrE Honanr. 

